1. Field of the Invention
The present invention relates to a method for recovering misdischarge is an ink jet recorder which eliminates non-discharge or misdischarge of ink to permit stable discharge of ink, and an ink jet recording apparatus using the same.
2. Related Background Art
In a prior art ink jet recorder such as that disclosed in U.S. Pat. No. 4,045,802, capping means for closing a periphery of an discharge orifice of a record head is provided to close the periphery in a non-record mode so that the record head is isolated from surrounding atmosphere while the record head is capped, and air layer in the capping means is filled with vapor of ink to keep a saturated vapor pressure so that drying and increase of viscosity of the ink in the discharge orifice are prevented.
However, in such a recorder, in a low humidity environment or when recording is paused for a long time it is not possible to sufficiently prevent the increase of viscosity of ink even if drying is prevented by the capping means, and hence it is difficult to completely prevent non-discharge or misdischarge of the ink from the nozzle in a record mode.
When a fine air bubble or dust is present in the ink in the discharge orifice, it causes disturbance of discharge of the ink in the record mode and it significantly deteriorates an image quality.
In order to solve such a problem, U.S. Pat. No. 4,600,931 discloses an ink jet recorder which renders the air layer in the capping means to be of low pressure so that the ink in the discharge orifice of the record head is sucked. U.S. Pat. No. 4,123,761 disclosed an ink jet recorder which has pumping means for an ink supply system including the record head and it is automatically or manually activated to pressurize the ink so that the ink is discharged from all nozzles of the record head. U.S. Pat. No. 4,176,363 discloses an ink jet recorder which effects pre-discharge in order to prevent non-discharge of the ink.
However, even such ink jet recorders are not always sufficient in that the recorders are always operable in a best condition regardless of a surrounding environment or recording condition. It is particularly difficult to completely eliminate fine air bubbles in the ink. Even if there is no fine air bubble at the start of recording, fine air bubbles may be generated and grown by cavitation during continuous recording operation, or ink droplets including air bubbles therein may be discharged from the discharge orifice to cause disturbance in the discharge of the ink.